Comparing the risk of low-back injury using model-based optimization: Improved technique versus exoskeleton...

Area of Science:

• Biomechanics
• Ergonomics
• Robotics

Background:

• Wearable robotic systems aim to mitigate low-back injury risk during lifting.
• The comparative effectiveness of exoskeleton assistance versus improved lifting technique remains unclear.

Purpose of the Study:

• To evaluate the effectiveness of exoskeleton assistance and technical lifting improvements in reducing low-back injury risk.
• To compare the impact of individual and combined interventions on lifting biomechanics.

Main Methods:

• A two-factor block study design was employed using simulation.
• Two models were simulated: human participant alone and human participant with SPEXOR exoskeleton.
• Optimal control problems formulated three cost functions for lifting technique: cumulative low-back load (CLBL), peak low-back load (PLBL), and hybrid (HYB).

Main Results:

• Exoskeleton assistance alone provided modest reductions in CLBL and PLBL.
• Technical improvements alone reduced CLBL but not PLBL.
• The combination of exoskeleton and technical improvements yielded the largest reductions in both CLBL and PLBL.
• The HYB cost function demonstrated the most balanced reduction in CLBL and PLBL.

Conclusions:

• Exoskeleton assistance and improved lifting techniques are beneficial for reducing low-back injury risk.
• Combining exoskeleton use with optimized lifting techniques offers synergistic benefits for mitigating low-back load.
• The HYB cost function represents a promising approach for developing effective lifting strategies.